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Session 80 - Central Stars of Planetary Nebulae.
Display session, Wednesday, January 17
North Banquet Hall, Convention Center
We present J and K images obtained under photometric conditions with the Lick 3m telescope of the Proto-Planetary Nebula IRAS 07131-0147 (galactic coordinates l=217, b=+4.7). This highly polarized bipolar reflection nebula is believed to be in the poorly understood evolutionary transition from the Asymptotic Giant Branch to Planetary Nebula. We find IRAS 07131-0147 to exhibit point reflection symmetry - a morphological characteristic rarely found in bipolar nebulae. Utilizing numerical integrations of single grain scattering models we derive a nearly face-on inclination angle of i < 5 degrees. The (J-K) color indicates that the central star (type M5 III) is negligibly reddened consistent with the `mid-butterfly' classification of the nebula (where the central star is relatively unobscured). Using the mean K magnitude of M5 galactic bulge giants, we estimate an approximate distance of 6 \pm 2 kpc, making this one of the most distant Proto-Planetary Nebulae known.
Program listing for Wednesday